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Most of the on-site data contained in the environmental contaminant tables have been taken fromthe October 1991 Removal Action Report by Law Environmental (10). That report includedprevious assessments from other contractors: Lozier Architects and Engineers, Environmetrics,Environmental Technology Corporation, and International Technology Corporation. Some of the reports have been referenced separately, as indicated in the tables. Some of the 1989data collected by Lozier Inc. was unusable because the sample identifications could not bedeciphered. However, the site is considered to be fully characterized with respect toenvironmental contaminants because all maximum concentrations have been reported.

RESPONSE TO COMMENTS RECEIVED DURING PUBLIC COMMENT PERIODFORNATIONAL ELECTRIC COILPETITIONED PUBLIC HEALTH ASSESSMENT

The National Electric Coil Public Health Assessment (PHA) was available for public review andcomment from December 14, 1992 through January 27, 1993. Copies of the PHA were sent tothe Harlan County Library, a repository for the site. A final copy of the PHA will also be sent tothe South East Community College Library in Cumberland, Kentucky. Comments were receivedfrom EPA, the Commonwealth of Kentucky (Department of Environmental Protection), CooperIndustries, a potentially responsible party, and two Harlan County residents.

Comments and responses on the PHA are summarized below. The comment letters can berequested from ATSDR through the Freedom of Information Act.

COMMENT: Verify off-site contamination levels by PCBs in soil.

RESPONSE: The PCBs levels reported in Table 10 for off-site soils (ND - 1.5 ppm) are correctand were samples taken near the fenceline of the mobile home park with NEC (Map from Lozierreport, dated 1990, sheet number 3, reference 11).

COMMENT: References to PCBs in river sediments downstream of NEC at levels of 54 ppm to720 ppm should be verified because commenters were not aware of data indicative of theselevels.

RESPONSE: PCBs in river sediments were inaccurately reported in previous versions of thePHA. PCB concentrations in Cumberland River sediments in the December 1989 data were lessthan 0.2 ppm. Sampling in 1993 indicated total PCBs in river sediments downstream of NEC as:not detected through an estimate of 0.21 ppm (Reference 12). ATSDR addressed the incorrectPCB concentrations in a flier and discussion with the community when we returned to explainour health assessment in March 1993.

COMMENT: The Kentcuky Department of Environmental Protection measured PCB sediment inthe river upstream of the NEC site at 0.028 ppm in 1989.

RESPONSE: Thank you for the information. We have used 1993 data which indicate themaximum upstream level to be 0.038 ppm.

COMMENT: The units are believed to be incorrect for on-site PCB contamination along theNEC and mobile home fence line and should be 0.029 and 0.100 ppm rather than 290 to 9100ppm. Additionally, the presence of a drainage ditch that flows from the NEC site to the MobileHome Park is questioned.

RESPONSE: The units are indeed incorrect, however, ATSDR believes that the correctionshould be 0.29 to 9.1 ppm (NUS sheet number 1, Lozier Inc. 1989, reference 11).

Our editors requested that we change the term swale so we used drainage ditch instead. However, since this term could be misleading (thought to be man-made), we will change it to alow lying area adjoining the two properties.

COMMENT: Please confirm the reference to tetrachloroethane in groundwater. The commenterbelieves it should be tetrachloroethene.

RESPONSE: The May 1991 Law Environmental Report (Table 4-2) indicates tetrachloroethaneis correct. However, we have no longer emphasized it in the discussion since it is not a major contaminant.

COMMENT: Identify source of comparison values for beryllium and manganese.

RESPONSE: The sources have been identified in the environmental contamination tables. ATSDR's Cancer Risk Evaluation Guide (CREG) for 1x10-6 excess cancer risk for beryllium insoil is approximately 0.16 ppm. ATSDR's comparison value for manganese in soil based onEPA's reference dose is 200 ppm. According to information in the March 1994 RemedialInvestigation Report (31), these comparison values are lower than background concentrations ofthese metals in the Dayhoit area. The health assessment was revised to acknowledge theseconcentrations as background levels. However, they have been retained for consideration ofhealth implications.

COMMENT: Please confirm and verify the number of wells found to be contaminated. It wouldappear that only 13 wells were contaminated.

RESPONSE: ATSDR's original estimate of fifteen wells excluding the Mobile Home Parkincluded two on-site wells. We have changed the number to 13 in the off-site contaminationsection.

COMMENT: Based on Cooper's data, wind direction has been found to be primarily northerly,rather than southerly (as stated in the public health assessment). Thus, the air quality in the mobile home park would not have been substantially affected.

RESPONSE: Substantial meteorological data was not provided to ATSDR until the draftRemedial Investigation Report, received in March 1994. ATSDR has updated the final release toreflect this information.

RESPONSE: Cancer occurs in one in three people's lifetime. It is very difficult for scientists todetermine who will get cancer. Further, if someone gets cancer, scientists and physicianstypically cannot know the cause of the person's cancer. We do know, however, that somesite-related chemicals are carcinogens. Please refer to the Toxicologic Evaluation section for adiscussion of vinyl chloride; asbestos; 1,1,2,2-tetrachloroethane; PCB's; and trichloroethene,which are known or probable human carcinogens. Please refer to the Community HealthConcerns Evaluation section for a discussion of cancer in the community.

Fibrocystic disease, warts, cysts, illnesses requiring a hysterectomy, and illnesses requiring theloss of a kidney are all health effects which could be due to a wide variety of underlying causes. In many cases, such as fibrocystic disease and endometriosis (an illness which often requires ahysterectomy), physicians do not know what causes the illness; none of the theories for theseeffects are based in environmental exposures. Warts are caused by viruses. Information aboutthe underlying condition which required the hysterectomy or the kidney removal would enable usto discuss the possible role, if any, that contamination had in the development of the condition.

A series of comments pertain to particular exposure pathways commenters felt were notacknowledged in the public health assessment. These potential exposures would have occurredin the past. No new exposure pathways or additional exposed segments of the population wereidentified through these comments. The following 5 comments pertain to exposure pathways.

COMMENT: There used to be a school downriver from NEC, and children drank the water fromthe pump right outside the school.

RESPONSE: The commenter describes an additional route by which children were exposed togroundwater. Without information about contaminant levels, we cannot evaluate the potentialhealth effects of that exposure. It is likely that exposures from that well would have been atsimilar levels as exposures at other wells in Dayhoit. Because that well is no longer used, wecontinue to consider exposure to groundwater a past concern.

COMMENT: In the past, children used to play and collect coal frequently in the river. Baptismswere performed in the river, too.

RESPONSE: We are aware that people were exposed to contaminants in the river, as discussedin the Completed Exposure Pathways section. We have included participants in baptism ritualsin the discussion.

COMMENT: There is a garden near the discharge pipe from NEC, and many people haveworked in the garden and eaten vegetables grown in it. There also used to be a chicken farm inDayhoit where people bought their eggs.

RESPONSE: The vegetable garden is discussed in the Food Chain Pathway section of theEnvironmental Pathways section. With no information about contaminant levels in air during theoperation of NEC, and no information about the feed supplied to the chickens, ATSDR cannotevaluate the likelihood of contaminated eggs.

COMMENT: In the past, air discharges from the facility would be blown into Dayhoit, and thatduring rainy and foggy times the discharge would be kept right on top of the community.

RESPONSE: Weather conditions such as inversions affect concentration and residence time ofair-borne contaminants; however, as stated in the Environmental Contamination and OtherHazards section, the potential effect air contamination had on public health cannot be evaluatedbecause of the lack of data collection during plant operations.

COMMENT: Residents used to collect copper in the dump site behind NEC, and the dump sitewas a continuous smoldering pit.

RESPONSE: The exposures those people would have sustained from the fumes areacknowledged in the Ambient Air Pathway. People also were exposed to whatever wastematerial they handled, although we have no information by which to evaluate the health impactof that exposure.

COMMENT: There was a drainage pipe from NEC downriver from the trailer park and thereforesoil testing should extend beyond the trailer park.

RESPONSE: The authors were aware of this drainage pipe. The pipe discharged directly to theRiver and the downstream sediments were characterized. Additionally, further off-site soiltesting was not recommended because even the Mobile Home Park contaminant concentrationswere low as reported in the Off-site Contamination section.

COMMENT: Death statistics do not always accurately reflect cancer information; for example, ifa person has cancer but died of heart failure, heart failure will be listed as the cause of death andcancer will not.

RESPONSE: The commenter is correct to point out that the death statistics do not alwaysaccurately reflect cancer information. According to the International Statistical Classification ofDiseases and Related Health Problems, tenth revision, mortality is coded to the underlying cause,that is, to the disease or injury which initiated the train of morbid events leading directly to death. For example, the death of a person with cancer who dies in a traffic accident would not be listedas a cancer death statistic. However, if a person dies of heart failure and if cancer were the causeof the heart failure, then the person's death would be considered a cancer death statistic. Thephysician completing the death certificate determines the underlying cause.

Public health investigations can be designed to identify all people who have cancer (cancerincidence) rather than all people who died of cancer (cancer mortality).

COMMENT: Insufficient documentation is presented to determine if the risk assessments areperformed according to standard procedures and calculations.

RESPONSE: ATSDR evaluated the health and environmental information according to standardprocedures and calculations as described in the ATSDR Public Health Assessment GuidanceManual. Additional discussion describing how we estimate exposure doses and calculateincreased cancer risks has been added to the Public Health Implications section.

COMMENT: How are ATSDR soil levels determined, and what are the chemical-specific soilaction levels? Particularly, what about PCB levels?

RESPONSE: As described in the Environmental Contamination and Other Hazards section,ATSDR selects contaminants of concern by comparing the concentration of the contaminant witha comparison value for noncarcinogenic and carcinogenic endpoints. These comparison valuesare media-specific concentrations used to select environmental contaminants for furtherevaluation, and are not used as predictors of adverse health effects or for setting clean up oraction levels. The EPA determines clean up and action levels. They have set the action level for PCBs at 10 ppm (12).

Non-carcinogenic comparison values (environmental media evaluation guides, EMEGs) arederived from minimal risk levels (MRLs) presented in the ATSDR Toxicological Profiles. AnMRL is defined as an estimate of daily human exposure to a chemical that is likely to be withoutan appreciable risk of deleterious effects over a specified duration of exposure. If no MRL hasbeen developed, the estimated exposure dose is then compared to a comparison value (environmental reference dose evaluation guide, EREG) derived from the EPA's reference dose. Carcinogenic comparison values (cancer risk evaluation guides, CREGs) are based on an excesscancer rate of one in a million persons and are calculated using a cancer slope factor developed by the EPA specifically for each cancer-causing chemical.

When evaluating soil exposures, ATSDR uses the assumptions stated in the EnvironmentalContamination and Other Hazards section. Using those assumptions and EPA's slope factor forPCBs, we derived a comparison value (CREG) of 0.09 ppm for PCBs.

COMMENT: Will air monitoring take place, even though it is not required by the KentuckyDivision for Air Quality?

RESPONSE: Yes, due to the air stripping operation, air monitoring conducted by EPA or theircontractors is necessary.

COMMENT: Sampling for chemicals of concern in wells should include trichloroethylene, vinylchloride and polychlorinated biphenyls as well as 1,2-dichloroethene.

RESPONSE: By recommending that well sampling differentiate between cis- andtrans-1,2-dichloroethene, we did not intend to imply that other chemicals need not be sampledfor. We have altered the recommendation to eliminate the ambiguity.

COMMENT: Is the USEPA "Guidance Manual for Assessing Human Health Risks fromChemically Contaminated Fish and Shellfish" to be used in assessing the fish tissue data, or are the Food and Drug Administration action levels to be used?

RESPONSE: ATSDR recommends using the USEPA "Guidance Manual for Assessing HumanHealth Risks from Chemically Contaminated Fish and Shellfish". The EPA and FDA concurwith this choice in situations such as the one presented here.

COMMENT: Although Giardia should not be discounted at the site, it is more likely that someother pathogenic bacteria would have caused health symptoms. Many amoeboid pathogens arequite common in Kentucky and may result in health problems in children that spend considerabletime in the water.

RESPONSE: We have amended the recommendation to include these pathogens and suggestedthat this issue be taken up by local health officials and citizens who wish to pursue it.

COMMENT: Since many of the trailers in the Holiday Trailer Park appear to be 10-15 years old,formaldehyde or some other organic may have seeped into homes from trailer insulation. Werecommend some of the trailers be monitored for possible contaminants unrelated to the NationalElectric Coil contamination and the contribution of these indoor air contaminants to healtheffects be assessed.

RESPONSE: The commenter's request is outside ATSDR's purview. After 10 to 15 years,formaldehyde would have already dispersed from these trailers. Formaldehyde can be a problemfor hypersensitive individuals particularly in new trailer homes and cars. Individuals who may be hypersensitive can contact the local or state health departments to learn how to reduce exposure.

COMMENT: The proposed sampling of soil at the Holiday Mobile Home Park is at a screeninglevel and provides insufficient information to perform a risk assessment.

RESPONSE: The off-site soil sampling completed by EPA (date) goes beyond a screening leveland provides sufficient information to determine if residents are being exposed to contaminantsat levels of health concern.